脊髓损伤大鼠膀胱顺应性与神经生长因子表达的相关性研究

摘要

Objective To explore the correlation between bladder compliance and nerve growth factor (NGF) expression in rats with spinal cord injury at different segments. Methods Included in this study were 180 female SD rats randomly divided into three groups:thoracolumbar injury group (n=60), sacral injury group (n=60) and the control group (n=60). Animal models of dorsal spinal cord injury were established by using standardized animal experimental apparatus. The site of spinal cord injury was T10-L1 for thoracolumbar injury, and S2-S4 for sacral injury. The control rats received removal of spinous process and vertebral lamina, and were free of injury to the spinal cord. Four weeks later, all rats underwent cystometry; then the bladders were harvested for preparation of tissue homogenate. The NGF expression level was determined by using ELISA. Results ①Thoracolumbar injury was characterized by low compli-ance bladder, while sacral injury resulted in high compliance bladder. ②ELISA showed that the NGF expression in bladder tissue homogenate was increased in thoracolumbar injury group and decreased in the sacral injury group. ③There was a negative correlation between bladder compliance and bladder tissue NGF expression in thoracolumbar in-jury (r=-0.655, P<0.05) and in sacral injury (r=-0.783, P<0.05). Conclusion High-level injury of spinal cord leads to reduced bladder compliance and increased NGF expression in bladder tissue. The opposite holds true with low-level injury of spinal cord. Bladder compliance is negatively correlated with NGF expression level in bladder tissue after spinal cord injury.%目的：探讨大鼠脊髓不同部位损伤后膀胱顺应性与膀胱神经生长因子（NGF）表达的关系。方法180只雌性SD大鼠按随机数字表分成3组，胸腰段损伤组60只，骶段损伤组60只，正常对照组60只。使用标准化脊髓损伤动物模型实验装置制备背侧脊髓损伤动物模型，胸腰段损伤组损伤部位为T 10～L 1，骶段损伤组损伤部位为S2-S4，对照组大鼠仅咬除棘突和椎板，不损伤脊髓。4周后作膀胱测压检测后，取出膀胱制备组织匀浆，酶联免疫吸附试验（ELISA）法测定NGF的表达量。结果①胸腰段损伤组以低顺应性膀胱为特征，骶段损伤组表现为高顺应性膀胱。②膀胱组织ELISA检测结果表明：胸腰段损伤组膀胱组织NGF表达量增加，骶段损伤组膀胱组织NGF表达量降低。③胸腰段脊髓损伤后膀胱顺应性和膀胱组织中NGF表达量呈负相关（r=-0．655， P＜0．05）；骶段脊髓损伤后膀胱顺应性和膀胱组织中NGF表达量呈负相关（r=-0．783，P＜0．05）。结论脊髓高位损伤后膀胱顺应性降低，膀胱组织NGF表达量升高；脊髓低位损伤后膀胱顺应性升高，膀胱组织NGF表达量降低；脊髓损伤后膀胱顺应性的改变与NGF的表达量呈负相关。